I had long wondered what the "quat" in loquat and kumquat meant, and why these two taxonomically distinct fruits shared that root. Apparently, quat is a romanization of the Chinese word for orange, or citrus fruit more broadly, and loquat essentially means "reed-" or "rush-orange", so named for its affinity for low-lying areas, while kumquat means "golden orange" and is associated with good fortune. While I assumed,upon learning this, that it was the origin of the kumquat's generic name, Fortunella, apparently the genus is named for Robert Fortune, who brought the kumquat to England from China in the mid 19th Century.
Does anyone know the etymology of the Nagami kumquat's species name, margarita? Does it have some association with sand or dunes, or with a Margaret (perhaps Robert Fortune's wife)?